Background Pulmonary embolism is a heterogeneous, potentially life-threatening entity which may have variable clinical manifestations and imaging appearances. Imaging plays an important role in the diagnosis of pulmonary emboli with advances in computed tomography pulmonary angiogram (CTPA) techniques leading to improvements in diagnostic sensitivity. The extent and distribution of emboli within the lungs have been minimally studied. CTPA is a commonly performed investigation, including in patient populations whose underlying condition may influence the diagnostic performance of the modality.1 Patients with chronic obstructive pulmonary disease (COPD)...

This study was approved by the Royal Perth Hospital Human Research Ethics Committee. A search of all CTPA studies performed between 1 January 2016 and 31 July 2017 at our tertiary institution, Royal Perth Hospital, was performed searching the local Radiology Information System platform. Studies that had been reported as demonstrating pulmonary emboli were identified and collated for independent imaging review by the thoracic subspecialist imaging team.A positive study was defined as one having a pulmonary arterial filling defect (Fig. 1) lacking appearances typical of...

A total of 1319 consecutive CTPA studies were performed during the study period, yielding a total of 202 positive studies (110 male, 92 female) for further analysis. The rate of positive studies was 15.3%. The cohort comprised subjects from emergency, inpatient and outpatient settings. A summary of associated CT features are presented in Table 1 . The mean age of patients included in the study was 59.4 years (median 61, range 18 – 97). Twenty-three patients (11.4%) demonstrated CT changes of established COPD. Thirty-four patients...

In our cohort of patients with pulmonary emboli evident on CTPA, 90% demonstrated lower lobe emboli and 90% demonstrated right-sided emboli. The right lower lobe had the highest prevalence of emboli (80%)of any anatomical lobe. An appreciation of this embolic predilection could improve CTPA detection efficiency amongst radiologists in a rapid reporting environment.

1.Hess, S, Frary EC, Gerke O, Madsen PH. State of the art imaging in pulmonary embolism: ventilation/perfusion single-photon emission computed tomography versus computed tomography angiography — controversies, results, and recommendations from a Systematic Review. Semin Thromb Hemost. 2016; 42(8): 833–845. Pubmed ID - 27764879 2. Hartmann I, Hagen P, Melissant C, et al. Diagnosing acute pulmonary embolism. Effect of chronic obstructive pulmonary disease on the performance of d-dimer testing, ventilation/perfusion scintigraphy, spiral computed tomographic angiography, and conventional angiography. Am J Respir Crit Care Med. 2000;...

DrSusan O’Hanlon BSc MBBS(Hons) - Radiology Senior Registrar DrTroy Wooding MBBS(Hons) - Radiology Registrar DrAnika Mittal BMedSc MD - Intern DrYuranga Weerakkody MBBS FRANZCR ESTI-Thoracic Imaging Fellowship - Consultant Radiologist